li{
	list-style: none;
	line-height: 100px;
	padding: 0 30px;
	color:#fff;
}
li:hover{
	background-color: #12b7f5;
}
nav{
	height: 100px;
	display: flex;
	justify-content: center;
	align-items: center;
	position: relative;
	z-index: 1;	
}
.bg{
	height: 900px;
	background-image: url(1.jpg);
	position: relative;
	bottom: 100px;
}
section{
	height: 300px;
}
.bg2{
	height: 900px;
	background-image: url(fisrtbg.jpg);
	background-attachment: fixed;/*背景相对于视口固定*/
}
.bg3{
	height: 900px;
	background-image: url(avds.jpg);
	background-attachment: fixed;/*背景相对于视口固定*/
}
.bg4{
	height: 900px;
	background-image: url(bg3_1600.jpg);
	background-attachment: fixed;/*背景相对于视口固定*/
}
.top{
	height: 600px;
	display: flex;
	justify-content: center;
	align-items: center;
}
.card img{
	width: 100%;
}
.card{
	width: 20%;
	border: 1px solid rgba(0,0,0,0.1);
	justify-content: center;
	align-items: center;
	margin: 0 20px;
}
.card .text{
	text-align: center;
}
footer{
	background-color: #000;
	height: 200px;
	display: flex;
	justify-content: space-between;
	flex-direction: column;
}
footer .icons{
	text-align: center;
	color: #cfcfcf;
	margin-top: 20px;
}
footer hr{
border-color: #cfcfcf;
width: 90%;
margin:0 auto;
}
footer p{
	text-align: center;
	color: #cfcfcf;
}